Nicolet is 5 ftir spectrometer

The effects of laboratory ageing and bio-flux additive under investigation were evaluated by Fourier-transform infrared spectroscopy (FTIR) using the attenuated total reflectance (ATR-FTIR) method. The Thermo-Scientific Nicolet iS 5 FTIR Spectrometer (Waltham, MA, USA) and the PIKE Technologies GladiATR (Madison, WI, USA) attenuated total reflectance accessory with a diamond window was used. The changes in the chemical structure of the asphalt binders were tracked using structural chemical indices characterizing the relative changes in the amounts of compounds related to oxidative ageing (sulfoxide and carbonyl indices) and an index specific to the bio-flux modification. Details regarding the analysis of the spectra are provided in Section 3.2. The spectrograms were recorded using 32 scans per sample at 4 cm⁻¹ resolution and three replicates were tested for each evaluated experiment.
Prior to any evaluations and calculations, all absorbance spectra have been normalized by setting the absorbance value of the asymmetric stretching vibration of the aliphatic structures at 2923 cm⁻¹ to 1.0 and multiplying the entire spectrum by an adequate factor as proposed by Hofko et al. [53 (link)].
The statistical analysis for assessing the significance of the measured effects was conducted based on a linear statistical model with an interaction term.

The investigation focused on the consistency characteristics of the joint sealants and the properties of their constituents and did not evaluate the properties related to the adhesion of sealants to various types of surfaces; such an evaluation requires a separate group of tests using primers.
The testing methodologies included:

The solvent extraction of the investigated joint sealant with the use of tetrachloroethylene as a solvent:
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The determination of the soluble binder content (EN 12697-1);

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The recovery of soluble bitumen with the use of a rotary evaporator (EN 12697-3+A1).

Basic properties of the joint sealant and soluble asphalt binder:
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Needle penetration at 25 °C (EN 1426);

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Cone penetration at 25 °C (EN 1426, EN 1388-2)—only joint sealants;

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Softening point, ring, and ball (EN 1427);

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Fraass breaking point (EN 12593);

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Elastic recovery at 25 °C (EN 13398).

Fourier transform infrared spectroscopy (FTIR) using the attenuated total reflectance (ATR-FTIR) method.

The vacuum evaporator distillation procedure suitable for the solvent was used in accordance with EN 12697-3+A1 (Table 2).
The Thermo-Scientific Nicolet iS 5 FTIR Spectrometer and the PIKE Technologies GladiATR attenuated total reflectance accessory with a diamond window was used for the Fourier transform infrared analysis. The FEI Quanta Feg 250 SEM scanning electron microscope was used for elemental analysis.

In this study, attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy was used to evaluate the composition of the foamed binders. The Thermo-Scientific Nicolet iS 5 FTIR Spectrometer (Waltham, MA, USA) and the PIKE Technologies GladiATR (Madison, WI, USA) attenuated total reflectance accessory with a diamond window was used. The bitumen samples after foaming were poured into 1 dm³ glass containers, reheated at 140 °C for 2 h, and homogenized for uniform distribution of water during the first stages of cooling at room temperature. The testing was conducted 3 days after foaming. Samples were transferred onto the ATR crystal mechanically, without reheating. Three different samples of each binder were tested, and the potential effects of foaming on the binders’ chemical composition, specifically due to oxidative aging, were measured by evaluating the formation of sulfoxide and carbonyl compounds [73 (link)]. Additionally, the presence of elastomeric additives was investigated in their specific absorption bands.
The quantitative evaluation of the mentioned compounds was conducted by calculating normalized indices as given in Table 4. The areas under the respective peaks were computed by the common tangent baseline method as proposed in the work of [74 ].